In the non-wovens industry machines have been used to produce non-woven fabrics from staple fibers for almost 100 years. The machines comprise a number of rollers which are provided with clothing and separate the fibers by carding and form a non-woven fabric on a doffer. Normal machines, also called “carding machines”, produce a non-woven fabric that before further strengthening in downstream machines has a distortion resistance ratio in the direction of travel to transverse to the direction of travel of 10:1. By means of random rollers and stuffing rollers according to DIN 64118 the ratio can be improved to 4:1. By means of air-laid non-woven fabrics as in applications DE2535544 and DE 3901313 indicated as examples, this ratio can be improved to 3:1.
A further old method for producing non-woven fabrics is the use of a carding machine with cross layers and optionally a non-woven section. The preferably longitudinally orientated non-woven fabric (in the direction of travel) is fed to a cross layer by means of at least one conveyor belt. This cross layer deposits the non-woven fabric in a number of layers by means of conveyor belts on a depositing belt running at 90° to the draw-off direction. A subsequent non-woven section stretches this non-woven fabric so that approximately 1:1 strength is achieved.